KYIV - As Russia steps up airstrikes and once again advances on the battlefield in Ukraine more than two years into its bloody invasion, there is no end to the fighting in sight. And President Volodymyr Zelenskyy’s options for what to do next — much less how to win the war — range from bad to worse.

Zelenskyy has said Ukraine will accept nothing less than the return of all its territory, including land that Russia has controlled since 2014. But with the battle lines changing little in the last year, militarily retaking the swaths of east and south Ukraine that Russia now occupies — about 20% of the country — appears increasingly unlikely.

Negotiating with Russian President Vladimir Putin to end the war — something Zelenskyy has rejected as long as Russian troops remain on Ukrainian land — is politically toxic. The Ukrainian public is hugely opposed to surrendering territory, and Putin shown no willingness to accept anything short of Ukraine’s capitulation to his demands.

The status quo is awful. With the fight now a grinding stalemate, Ukrainians are dying on the battlefield daily. But a cease-fire is also a nonstarter, Ukrainians say, because it would just give the Russians time to replenish their forces.

Ukrainian and Western officials view Zelenskyy as largely stuck. Aid from the United States, Ukraine’s most important military backer, has been stalled for months by Republicans in Congress. Previously approved modern fighter jets — the U.S.-made F-16 — are expected to enter combat later this year — but in limited quantity, meaning they will not be a game changer. NATO countries are still exercising restraint in their assistance, evidenced by the recent uproar after French President Emmanuel Macron said European nations should not rule out sending troops.

“How will Zelenskyy get out of this situation? I have no idea,” said a Ukrainian lawmaker who, like other officials and diplomats interviewed for this article, spoke on the condition of anonymity to be candid about the highly sensitive politics. “And of course it concerns me.”

Most tricky for Zelenskyy will be managing his own country’s expectations. Support for him among Ukrainians remains high, but after two years of war and steep casualties, the “solidarity is fraying,” a Western diplomat in Kyiv said.

Tymofiy Mylovanov, a professor at the Kyiv School of Economics and former government minister, said the fight could drag on for many years. “This is an unpleasant thought but when some people say it might take decades, no one challenges that,” Mylovanov said.

This was supposed to be an election year for Zelenskyy, but Ukraine’s constitution prohibits elections under martial law, and some officials here worry that Russia will try to cast Zelensky as an illegitimate ruler once he is serving longer than his elected five-year term — despite the inherent hypocrisy in Putin’s own repeated disregard for term limits.

Zelenskyy will also have to live up to his own promise — which he restates regularly — of returning Ukraine to its 1991 borders, including Crimea, the Ukrainian peninsula that Russia illegally invaded and claimed as its own 10 years ago.

“Smart people know that’s not realistic,” the Ukrainian lawmaker said, adding: The political leadership “needed to adjust this rhetoric at some point.”

Pessimism about Ukraine’s battlefield chances has increased in recent months as Russian forces have regained the initiative on the battlefield, largely because Ukrainians are short on troops and ammunition.

Ukraine is reliant on its Western partners for weapons, but a $60 billion security package from the United States has been stalled in Congress for six months. Meanwhile, Ukraine’s government is struggling to address its personnel shortages as measures to mobilize more soldiers have divided society.

Kyiv is now bracing for the possibility that aid from the United States could be cut off. House Speaker Mike Johnson (R-La.) said recently that the package could be put to a vote next week but it is expected to face revisions, such as perhaps providing the money as a loan, which would add to Ukraine’s already huge debt.

Even if the aid is approved soon, the delay has sent a clear signal that future assistance is not guaranteed, especially with the U.S. presidential election this year. Officials also worry that Europe lacks the production capacity to compensate for a U.S. shortfall, especially in artillery and air-defense ammunition — Ukraine’s biggest needs.

Zelenskyy has said Ukraine is prioritizing domestic production but so far makes only a small fraction of its needs. Russian forces are now firing six times as much as the Ukrainians along the front line.

“Look, we have been without ammunition for half a year already. Not enough of it, at least,” a senior Ukrainian official said. “Well okay, it will get worse. And so what? What other options are there? If partners who have promised to give us ammunition don’t give it, of course the situation gets worse. But the image of the U.S. will get worse in the world.”

A year ago, the mood in Kyiv was cautiously optimistic as Ukraine readied a large counteroffensive with modern tanks and fighting vehicles freshly provided by Western partners. But that assault failed to make significant gains, and the new weapons did not prove decisive.

Ukrainian strikes deep into Russia targeting military infrastructure and logistics such as oil depots have increased, but Kyiv’s forces are still under pressure along the front line and lately have been pushed backward.

Ukrainians have resigned themselves to a long war. Some have been fighting since 2014, when Russia first stoked conflict in eastern Ukraine.

“Ukraine does not have the power to make another offensive,” said one Western ambassador. “There are two scenarios. One scenario is they get the support to maintain defensive lines. … The second is there is not enough support and Ukraine will defend itself anyway, desperately and with less manpower.”

If Kyiv faces Russian forces with inadequate support this year, the ambassador said, there will be increased casualties and territorial losses, putting Ukraine on the back foot.

Ukraine and its partners must prepare for 2025 as “another year of war, not peace talks,” the ambassador said. “If [the] West wants peace, it should not only respond to current Ukrainian needs, but use 2024 to provide Ukraine with everything that’s necessary to enter into offensive mode and make substantial gains in 2025.”

But Ukraine must meet some needs on its own. Field commanders have reported troop shortages along the front line, especially infantry who deploy at the forwardmost positions. Military commanders have pushed for a large-scale mobilization but Zelenskyy has voiced doubt even as Kyiv says Moscow is planning to conscript 300,000 more soldiers.

Zelenskyy recently signed a law that lowered Ukraine’s minimum draft age to 25, but he has said mobilizing some 500,000 more troops, as Ukraine’s former commander in chief suggested, won’t happen. Col. Gen. Oleksandr Syrsky, the new military chief, has said the 500,000 figure was “significantly reduced” after a personnel audit. Meanwhile, a draft law in parliament to widen the parameters of who can be conscripted has undergone thousands of amendments.

A second Western diplomat in Kyiv said Zelenskyy’s administration and Ukraine’s parliament are playing “political ping pong” on mobilization because it is unpopular. While thousands volunteered to fight early in the war, few who have not already signed up want to now.

“Nobody wants to really bear the responsibility at this point,” said the diplomat, who was not authorized to speak publicly.

“But it will have to be done,” the diplomat said. “I mean, you cannot go on like this. I hear about people who are at the front who just can’t take it anymore. And then when they come back here on leave and they see all these young guys who could be there, I would be resentful of that. So you get social tensions surrounding that as well.”

A large-scale mobilization would also pose economic challenges. The money for soldier salaries cannot directly come from foreign aid, and some industries already face labor shortages. Ukraine’s economy is under strain from repeated missile and drone attacks targeting energy infrastructure, which also scare away foreign business investment.

So how long can Ukraine withstand being at war? The Ukrainian lawmaker said the country will not survive the status quo for another 10 years. Others, however, think the fight could go on even longer.

“No one will concede territory, but people understand that getting it back might take a long time,” said Mylovanov, the economics professor. “What form can that take? Views differ here. A long war with eventually a victory? A sudden collapse in the Russian power structure? A successful counteroffensive? But that requires a very different type of support than what Ukraine has now.”

The senior Ukrainian official said: “Everyone wants quick solutions, but everyone has come to understand that there won’t be quick ones.”

Siobhán O’Grady, David L. Stern and Anastacia Galouchka contributed to this report.